The current invention relates to an arrangement in a separator, in particular a gravity separator, to which separator is supplied well fluid containing sand.
The invention primarily aims at giving instructions on a technique where accumulation of sand in a gravity separator is avoided. The sand entering the separator with the main stream from, e.g. a production well, tend to settle on pipe or separator walls. Such sand sediments can be difficult to remove due to adhesive and cohesive forces.
From the patent literature the problem named above concerning accumulation of sand in a gravity separator, seems not to be given particular attention. There exist a number of methods that deals with other types of separators, e.g. cyclones trough which are fed a continuous stream of fluid containing solid particles such that accumulation of sand is avoided, but not in connection with gravity separators.
From NO patent 176 451 there is known a device for processing of well fluids from oil or gas wells on the sea-floor utilising a separate accumulation tank for solid components or particles, placed below a separator tank.
From the bottom of the separator tank to the top of the accumulation tank there is placed a mainly vertical connection pipe with a cut off valve, and when this cut off valve is closed, collected components or particles can be removed from the accumulation tank. In other words this relates to a successive collection of solid components or particles, and a successive emptying of the accumulation tank, respectively.
An object of the present invention is to provide an arrangement in a gravity separator, where sand can be removed from the separator with simple means.
Another object of the invention relates to continuous removal of sand from the gravity separator and continuous removal of the precipitated sand from the area of the separator.
Still another object of the present invention relates to transferring the problem of sand sedimentation in a gravity separator to other sections of the installation comprising the gravity separator, where it is easier to handle this problem.
These objects are achieved in an arrangement as initially mentioned, which according to the invention is characterised in that the separator comprises a lower conical part that leads into an oblique or mainly vertically arranged bottom pipe for practically continuous release from the bottom of sand entrained in water, mainly sand-carrying water.
Additional advantages and features of the present invention will appear from the following disclosure in connection with the appended drawings, as well as the appended claims.